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Toxic effects of freshwater pollutants on the survival, behaviour and reproduction of Gammarus pulex (L.) and Asellus aquaticus (L.)

The toxic effects of cadmium on aspects of the survival, behaviour and reproduction of Gammarus pulex and Asellus aquaticus are described in some detail. Some of the laboratory procedures were validated in field experiments. The presence of the parasites Pomphorhynchus laevis and Echinorhynchu_s1truttae does not modify the toxicity of cadmium (0.01-1.0 mgl ) to their intermediate-Fost G. pu7ex. Pretreatment for 24 hours with 0-47 μgl cadmium alters the distribution of separation times when precopula pairs of G. pu7ex are disrupted by the invertebrate anaesthetic 2- phenoxyethanol. Precop1la is directly disrupted by exposure to cadmium (0.1-12.7 mgl )_ýut recovery can follow. Pretreatment with cadmium (3-140 μgl ) for 24 hours, of similarly sizeci male G. pulex and subsequent exposure to 0.13 and 2.23 μgl while in competition for access to a female may increase tolerance and enhance reproductive success, or initiate irreversible toxic effects and impair competitive ability. Exposure of female G. pulex-1to 2.0 and 9.6 μg1 , and female A. aquaticus to 40.2 pgl cadmium pre-fertilization reduces their fecundity. Brood development times of G. pulex and A. aquaticus exposed to 2.1 and 12.4 μg1-1 cadmium postfertilization are extended by 2 and 2.7 days respectively. The embryonic development and abortion during brooding are described in detail for A. aquaticus. An explanation of reduced final brood size in Asel7us is Postulated. Growth of juveniles of both test species exposed during brooding is assessed. Single and repeated 24 hour field simulations of acidic deposition demonstrate increased host sensitivity of G. pulex infected with P. 7aevis. The effects of low pH and elevated aluminium concentrations are mitigated to some extent by liming. Six hour field simulations of the individual components of farm waste demonstrated that infected gammarids were more susceptible under conditions of low dissolved oxygen than uninfected conspecifics.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:320266
Date January 1990
CreatorsPoulton, Madeline June
PublisherCardiff University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation

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